I don't think a lack of lines is the problem, and I think that it won't help.

Do you mean this?

Yes. It is clear from the project file that the optimizer has "solved" your project with a nonsense result. That usually happens because of bad input data which is used by the optimizer as a "starting point" from which to "solve" the project. A bad starting point usually leads to an incorrect solution. Bad input data is typically one (or more) of the following: incorrect field-of-view, incorrect lens projection, or incorrectly drawn line. I can't tell what has happened here, but my guess is that at least one of the lines is probably bad (perhaps connecting the ends of two different star trails).

It might be easiest to start again and add only a few lines (say 8-10 at first), and see if you can get a reasonable optimization result. After that you can add some more lines to get a more precisely optimized result. I also recommend not optimizing field-of-view. Or, only doing so as a last step and paying attention to make sure that the optimized value for FOV isn't unreasonable.